Do Capuchin Monkeys Display a Sensitivity to Unequal Effort Contributions in a Snowdrift Scenario? Open Access

Longacre, Ian (2010)

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The existence of altruism presents a conundrum for evolutionary theory, and
assessing the existence and features of this behavior in non-human primates can
potentially contribute to evolutionary explanations of human cooperative behavior.
Basing our experiment on the "Snowdrift" game, we looked for whether individual
capuchin monkeys adjust their own behavior in response to the effort levels of a
partner monkey in a cooperative task. We found no evidence that the capuchins
adjust their own behavior based on an assessment of a partner's contributions.
Instead, the monkeys behavior was consistent with individual learning that is based
on the food rewards received for behavior within each session.

Table of Contents

Abstract ii
Table of Contents iii
List of Figures iv
List of Tables v

Background 1
Aims and Rationale 7

Subjects and Apparatus 10
Testing 12
Data Collection 17
Analyses 17
Results 22

Data Interpretation 27
Summary and Conclusions 31
References 33

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